Low-temperature thermoelectric refrigeration material and preparation method and application thereof

Abstract

The invention relates to a low-temperature thermoelectric refrigeration material and a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing Yb, In and Cu according to a stoichiometric ratio, putting the mixture into a tantalum crucible, carrying out electric arc melting in a vacuum sealed environment to obtain a YbInCu4 cast ingot, grinding to obtain YbInCu4 powder, and carrying out hot pressed sintering to obtain a YbInCu4 block, namely the target product, namely the low-temperature thermoelectric refrigeration material. The thermoelectric power factor of the low-temperature thermoelectric refrigeration material is 12-190 [mu] W.cm <-1 >. K <-2 > and the thermal conductivity is 5-8 W.cm <-1 >. K <-1 > within the temperature range of 38-40 K. Compared with the prior art, the thermoelectric refrigeration effect is effectively enhanced. Under the low temperature of about 38K, the device shows a stable temperature difference of 5-6K, the refrigeration performance of the device is far superior to that of an optimal Bi (1-x) Sbx-based Peltier refrigeration device at the low temperature at present, and the device shows the Thomson effect and has a huge potential of expanding thermoelectric refrigeration application to the low-temperature field.

Description

Technical Field

[0001] The present invention relates to the field of thermoelectric refrigeration technology, and in particular to a low-temperature thermoelectric refrigeration material and a preparation method and application thereof. Background Art

[0002] During the thermodynamic cycle, heat engines can achieve the conversion of thermal energy into other forms of energy through the entropy change of the working medium, thereby achieving the purpose of refrigeration / pumping heat. Key applications such as liquid helium storage, superconducting magnet cooling, and quantum computing rely on cryogenic refrigeration technology to provide a stable low-temperature environment, usually below 123K. At present, mechanical refrigeration technology is still the mainstream in the field of cryogenic refrigeration. This type of technology induces a phase change of the working fluid through the compressor transmission to achieve the refrigeration effect. Typical technologies include Stirling refrigerators and Gifford-McMahon refrigerators. However, the complex transmission system of mechanical refrigeration devices can lead to reliability problems, and the regular replenishment and replacement of refrigerants increase maintenance costs in extreme environments.

[0003] Given these limitations, the development of alternative or complementary technologies that do not require compressors has become an urgent need. Thermoelectric effect is essentially a heat engine or pump that uses carriers in the material as a working medium, which can achieve cooling or heat pumping without relying on traditional compressors. Due to its solid-state structure, thermoelectric cooling technology has the advantages of no noise, no vibration, no emissions, and high reliability, and is particularly suitable for local cooling and thermal management applications in low temperature and extreme environments.

[0004] Traditional thermoelectric coolers are based on the Peltier effect. Due to the mismatch in chemical potential between the thermoelectric material and the electrode, the entropy change of the carriers is driven by the current, absorbing heat at the junction. The Peltier effect further established the basic guiding principle for promoting thermoelectric cooling, that is, to maximize the Peltier cooling temperature difference by improving the thermoelectric figure of merit (zT) of the material. However, improving zT at low temperatures has always been a huge challenge, and no thermoelectric cooler has yet demonstrated a cooling temperature difference of more than 3K below 50K. In the 1850s, Lord Kelvin predicted and explained the existence of a cooling effect (Thomson effect) inside the material. In addition to the Peltier effect at the interface, the entropy change of the carriers inside the material will also produce cooling. The Thomson effect is a volume effect that measures the entropy change inside the thermoelectric material: for most homogeneous materials, the Thomson effect is small enough to be negligible; materials that show a significant difference in Seebeck coefficients at the hot and cold ends can show a significant Thomson effect. Similar to traditional compressor refrigerators based on phase change working media, by triggering the phase change of carriers inside the material, a significant entropy change can be generated, thereby greatly enhancing the Thomson effect and improving the overall refrigeration performance. Summary of the invention

[0005] The purpose of the present invention is to provide a low-temperature thermoelectric refrigeration material and its preparation method and application in order to overcome the defects of the above-mentioned prior art, and effectively realize the enhancement of the thermoelectric refrigeration effect. At a low temperature of about 38K, the device exhibits a stable temperature difference of 5 to 6K, and its refrigeration performance is far better than the current optimal Bi1-xSbx-based Peltier refrigeration device at low temperature, showing the great potential of the Thomson effect to expand the application of thermoelectric refrigeration to the low temperature field.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing a low-temperature thermoelectric refrigeration material. Yb, In and Cu are uniformly mixed according to a stoichiometric ratio and placed in a tantalum crucible. Arc melting is performed in a vacuum sealed environment to obtain a YbInCu4 ingot, which is ground to obtain YbInCu4 powder, and hot pressing and sintering is performed to obtain a YbInCu4 block, i.e., the target product, a low-temperature thermoelectric refrigeration material.

[0008] Furthermore, the arc melting comprises the following steps:

[0009] The uniformly mixed Yb, In and Cu are placed in a tantalum crucible, and the tantalum crucible is vacuum-sealed in an arc melting system;

[0010] The vacuum-sealed tantalum crucible is placed in a container, and after evacuation, it is sealed with a flammable organic gas;

[0011] The sealed container is water quenched at 1000-1200°C;

[0012] The container obtained after water quenching is annealed at 750-950°C to obtain a YbInCu4 ingot.

[0013] Furthermore, the container includes a quartz tube and an alumina crucible;

[0014] The combustible organic gas includes propane and hydrogen.

[0015] Furthermore, the sealed container is kept at 1000-1200° C. for 1-5 hours and water quenched.

[0016] Furthermore, the annealing time is 5 to 20 days.

[0017] Furthermore, the molar ratio of Yb, In and Cu is 1:0.8-1.2:3-5, preferably 1:0.9-1.1:3.5-4.5, and more preferably 1:1:4.

[0018] Furthermore, the purity of Yb is ≥99.95%, the purity of In is ≥99.99%, and the purity of Cu is ≥99.99%.

[0019] Furthermore, the specific conditions of the hot pressing sintering are: temperature of 500-800° C., uniaxial pressure of 60-100 MPa, and hot pressing sintering time of 30-120 min.

[0020] The second technical solution of the present invention is to provide a low-temperature thermoelectric refrigeration material, which is prepared by the preparation method.

[0021] Furthermore, the density of the low-temperature thermoelectric refrigeration material is greater than 98%.

[0022] Furthermore, the low-temperature thermoelectric refrigeration material exhibits a significant Thomson effect in the temperature range of 38 to 40 K, and the thermoelectric power factor is 120 to 190 μW·cm-1·K-2 and the thermal conductivity is 5 to 8 W·cm-1·K-1 in the temperature range of 38 to 40 K. The low-temperature thermoelectric refrigeration material utilizes the change in the hybridization between mobile electrons and Yb-4f electrons to achieve electronic phase change.

[0023] The third technical solution of the present invention is to provide an application of a low-temperature thermoelectric refrigeration material in the field of thermoelectric refrigeration, wherein the low-temperature thermoelectric refrigeration material is used to prepare a low-temperature thermoelectric refrigeration device. The low-temperature thermoelectric refrigeration device has high-efficiency thermoelectric performance when working at low temperatures, has a significant Thomson effect, and can maintain low resistivity and high thermal conductivity at high current density, thereby achieving rapid temperature difference response and stable refrigeration effect.

[0024] Furthermore, the low-temperature thermoelectric refrigeration device comprises:

[0025] Vacuum chamber;

[0026] A heat sink end located inside the vacuum chamber;

[0027] And a leg device connected to the heat sink end by a thermally conductive adhesive, the leg device is obtained by cutting the low-temperature thermoelectric refrigeration material, and the shape and size of the cutting can be determined according to the actual process. The low-temperature thermoelectric refrigeration device can effectively reduce heat loss and stabilize the hot end temperature and the cold end temperature. In order to maximize the thermoelectric refrigeration performance and reduce temperature fluctuations, a stable temperature difference output is obtained.

[0028] Furthermore, when the leg device is in the temperature range of 38 to 40 K and the current condition is 40 to 500, the maximum temperature difference is 5 to 6 K.

[0029] Furthermore, when the optimized current condition is 450 mA, the maximum temperature difference can reach 6 K when the temperature of the heat sink end is 38.4 K.

[0030] Furthermore, the heat sink end is a copper heat sink end.

[0031] Furthermore, the method of using the low-temperature thermoelectric refrigeration device for refrigeration is: applying current in the temperature range of 38 to 40 K at the heat sink end, and controlling the low-temperature thermoelectric refrigeration device to achieve the best refrigeration effect under a stable working current. By adjusting the working current, the Thomson effect can be optimized to achieve the maximum temperature difference.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) The present invention utilizes the discontinuous phase transition of the electronic state in the low-temperature thermoelectric refrigeration material at 38-40K to significantly enhance the Thomson refrigeration effect. The Thomson effect is used to achieve a high efficiency of up to 190μW·cm at low temperatures (38-40K) in the low-temperature thermoelectric refrigeration material (YbInCu4). -1 ·K -2 (120~190μW·cm -1 ·K -2 ) and 5~8W·cm -1 ·K -1 The high thermal conductivity ensures the fast response speed of the low-temperature thermoelectric cooling device. The results show that the low-temperature thermoelectric device can reach the maximum temperature difference in just a few seconds after power is turned on. This rapid response mechanism ensures the rapid temperature difference control of the device in practical applications.

[0034] (2) The Thomson effect of the low-temperature thermoelectric refrigeration material (YbInCu4) at 38.4K in the present invention is the strongest, so the refrigeration performance of the low-temperature thermoelectric device is optimized. By optimizing the working current conditions, the single-leg thermoelectric leg of the present invention can stably achieve a maximum temperature difference of 6K at a temperature of 38.4K, which is far superior to the Bi-Sb-based Peltier refrigeration device with optimized performance at low temperatures. This phenomenon is mainly due to the contribution of the Thomson effect, thereby achieving more efficient refrigeration performance.

[0035] (3) In the present invention, when driven by a relatively large working current, the low-temperature thermoelectric device can stably cool to 33.5K-34K when the temperature of the heat sink end is 38.4K and 36.5K, demonstrating the temperature control stability of the material and its device in the present invention under different temperature and current conditions. This precise temperature control capability provides an important reference for the design and operation of refrigeration systems in practical applications.

[0036] (4) The present invention uniformly mixes Yb, In, and Cu and places them in a tantalum crucible, and arc melts them in a vacuum sealed environment, which effectively prevents Yb, In, and Cu from reacting with containers such as quartz tubes, thereby improving the purity of the product, making it as close to the target phase as possible, and preventing the influence of impurities on the low-temperature transport of carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the low-temperature thermoelectric refrigeration device shown in Example 1;

[0038] Figure 2 The crystal structure and phase characterization diagram of the YbInCu4 powder shown in Example 1, (a) the crystal structure of the YbInCu4 powder, (b) the variable temperature X-ray diffraction pattern of the YbInCu4 powder, (c) the variable temperature X-ray diffraction contour diagram of the YbInCu4 material, (d) the scanning electron microscopy morphology of the YbInCu4 bulk;

[0039] Figure 3 Magnetic properties of the YbInCu4 bulk in Example 1, (a) logarithmic coordinate diagram of the effective magnetic moment of the YbInCu4 bulk varying with temperature, (b) isothermal resistivity and Seebeck coefficient dependent on magnetic field at 38.4K;

[0040] Figure 4 The electronic phase transition characteristics of the YnInCu4 bulk in Example 1, (a) the magnetic reversal susceptibility of the YbInCu4 bulk changing with temperature, (b) the characteristic coupling temperature of the YbInCu4 bulk, (c) the reconstructed energy band of the YbInCu4 bulk;

[0041] Figure 5 The transport properties and thermoelectric performance of the YnInCu4 bulk in Example 1, (a) the Hall carrier concentration of the YbInCu4 bulk depending on temperature, (b) the isothermal resistivity of the YbInCu4 bulk depending on temperature, (c) the Seebeck coefficient of the YbInCu4 bulk depending on temperature, (d) the thermal conductivity of the YbInCu4 bulk depending on temperature, (e) the thermoelectric power factor of the YbInCu4 bulk depending on temperature, (f) the thermoelectric performance figure of merit of the YbInCu4 bulk depending on temperature;

[0042] Figure 6 The cooling performance of the YnInCu4 single-leg device in Example 1, (a) the cooling temperature change curve of the YbInCu4 single-leg device, (b) the cooling temperature difference and Seebeck coefficient change of the YbInCu4 single-leg device at different heat sink end temperatures, (c) the cooling temperature difference of the YbInCu4 in Example 1 with the change of current at different heat sink end temperatures;

[0043] Figure 7The cooling temperature curves of the YnInCu4 single-leg device in Example 1 when the heat sink end temperature is 38.4K under different working current driving conditions are shown in Figure 1. (a) 120mA, (b) 250mA, (c) 500mA, and (d) cooling temperature variation with time curves under each working current.

[0044] Figure 8 The figure shows the change of the cooling temperature difference of the YbInCu4 low-temperature thermoelectric refrigeration device in Example 1 with the current and the temperature of the heat sink end.

[0045] Marking instructions in the figure: 1-single-leg device, 2-thermal conductive adhesive, 3-heat sink end, 4-vacuum cavity. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments. Based on the given embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0047] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art.

[0048] Example 1

[0049] A method for preparing a low-temperature thermoelectric refrigeration material comprises the following steps:

[0050] (1) According to the stoichiometric ratio of 1:1:4, high-purity Yb (99.95%), In (99.99%) and Cu (99.99%) raw materials were cut into pieces of about 3 mm in size, mixed evenly and loaded into a tantalum crucible.

[0051] (2) The tantalum crucible is vacuum-sealed in the arc melting system.

[0052] (3) placing the tantalum crucible obtained in step (2) in a quartz tube, evacuating the tube and sealing the tube with propane.

[0053] (4) The quartz tube obtained in step (3) is placed in a tube furnace, kept at 1100° C. for two hours, and then water quenched.

[0054] (5) The quartz tube obtained in step (4) is placed in a tube furnace and annealed at 850° C. for 10 days to obtain a YbInCu4 ingot.

[0055] (6) The ingot obtained in step (5) is manually ground into fine powder to obtain YnInCu4 powder, which is then hot-pressed and sintered at 650°C under a uniaxial pressure of 80 MPa for 50 minutes to obtain a YbInCu4 block with a diameter of 12 mm, a thickness of 1 mm, and a density of 99%, i.e., a low-temperature thermoelectric refrigeration material.

[0056] The low-temperature thermoelectric refrigeration material is used to prepare a low-temperature thermoelectric refrigeration device. The YbInCu4 wafer obtained in step (6) is cut into 0.6*1.25*10mm pieces using a diamond wire saw. 3 A rectangular parallelepiped is formed to obtain a YbInCu4 single-leg device 1, i.e. a single-leg thermoelectric leg.

[0057] The prepared single-leg device 1 is connected to the heat sink end 3 through the thermal conductive adhesive 2, and is placed in a vacuum cavity 4 to obtain a low-temperature thermoelectric refrigeration device.

[0058] like Figure 1 As shown, the low-temperature thermoelectric refrigeration device includes:

[0059] Vacuum chamber 4;

[0060] The heat sink end 3 located inside the vacuum cavity 4 is a copper heat sink end in this embodiment, which is a copper sheet;

[0061] And a leg device 1 connected to the heat sink end 3 through a thermal conductive adhesive 2, wherein the leg device 1 is cut from the low-temperature thermoelectric refrigeration material. The low-temperature thermoelectric refrigeration device can effectively reduce heat loss and stabilize the temperature of the heat sink end 3 and the cold end temperature. To maximize the thermoelectric refrigeration performance and reduce temperature fluctuations, a stable temperature difference output is obtained. In this embodiment, the thermal conductive adhesive 2 uses STYCAST 2850FT BLK18#8 thermal conductive epoxy resin purchased from Digi-Key Electronics (Shanghai Co., Ltd.).

[0062] Figure 2 The crystal structure and phase characterization of the YnInCu4 powder in Example 1. Figure 2 (a) is the crystal structure of YnInCu4 powder. The sample powder was subjected to X-ray diffraction in the range of 26K to 300K. Figure 2 (b) and Figure 2 (c) The results show that the material crystallizes in the cubic structure C15b in both the high-temperature and low-temperature phases, with Yb at the 4c ​​position, In at the 4a position, and Cu at the 16e position, indicating that there is no lattice phase transition in the material. Scanning electron microscopy (SEM) images ( Figure 2 (d)), further confirming the uniformity of its composition.

[0063] Figure 3 Magnetic properties of the YbInCu4 bulk in Example 1. Figure 3 (a) is the logarithmic coordinate diagram of the effective magnetic moment of YbInCu4 bulk changing with temperature; Figure 3 (b) is the magnetic field-dependent isothermal resistivity and Seebeck coefficient of YbInCu4 bulk at 38.4K. The test method is a vibrating sample magnetometer test in a helium exchange atmosphere. The phase transition is accompanied by a change in the indirect band gap due to the change in the hybridization between the mobile electrons and the Yb-4f electrons. This change is expressed in k B T coupling is the feature, where k B is the Boltzmann constant, T coupling is the characteristic coupling temperature. According to the magnetic susceptibility measurement, the T coupling 5K and 400K respectively. coupling The mutation indicates a discontinuous phase transition of electrons from Curie paramagnetism to Pauli paramagnetism, without the appearance of magnetic long-range order, indicating that there is no magnetic phase transition in the material.

[0064] Figure 4 is the electronic phase transition characteristic of the YnInCu4 bulk in Example 1, Figure 4 (a) is the magnetic reversibility of YbInCu4 bulk as it changes with temperature. Figure 4 (b) is the characteristic coupling temperature of YbInCu4 bulk, Figure 4 (c) is the reconstructed energy band of YbInCu4 bulk. coupling The sudden change from the high temperature phase of 5K to the low temperature phase of 400K indicates that a discontinuous phase transition has occurred in the electronic state. This phenomenon is observed in the YnInCu4 bulk of the present invention when the temperature is about 40K.

[0065] Figure 5 The transport properties and thermoelectric performance of YnInCu4 in Example 1. Figure 5 (a) is the temperature-dependent Hall carrier concentration of YbInCu4 bulk. Figure 5 (b) is the temperature-dependent isothermal resistivity of YbInCu4 bulk. Figure 5 (c) is the temperature-dependent Seebeck coefficient of YbInCu4 material. Figure 5 (d) is the temperature-dependent thermal conductivity of YbInCu4 bulk. Figure 5 (e) is the temperature-dependent thermoelectric power factor of YbInCu4 bulk. Figure 5(f) is the temperature-dependent thermoelectric performance figure of merit of YbInCu4 bulk. The sudden change in Hall carrier concentration corresponds to the change in chemical potential, which can be explained by the change in the 4f electron occupation state of Yb, further leading to an order of magnitude change in resistivity. The result also clearly shows the temperature range where the Peltier effect or Thomson effect is dominant: near the phase transition temperature, due to the large entropy change caused by the electronic phase transition, the steep slope of the Seebeck coefficient reflects the significant enhancement of the Thomson effect, resulting in a normalized Thomson coefficient (τ / T=dα / dT) near the electronic phase transition temperature. The positive and negative Thomson coefficients correspond to the Thomson heat flow and the Peltier heat flow in the same or opposite direction, respectively, thereby producing a synergistic or compensatory effect on the cooling capacity. In traditional thermoelectric materials without electronic phase transitions, the thermoelectric figure of merit usually increases with increasing temperature until a bipolar effect appears. In the YbInCu4 bulk of the present invention, the entropy mutation caused by the electronic phase transition causes the thermoelectric figure of merit to reach a peak during the phase transition.

[0066] Figure 6 is the cooling performance of the YnInCu4 single-leg device 1 in Example 1, Figure 6 (a) is the cooling temperature variation curve of the YbInCu4 single-leg device 1, Figure 6 (b) shows the cooling temperature difference and Seebeck coefficient change of the YbInCu4 single-leg device 1 at different heat sink end 3 temperatures. Figure 6 (c) is the cooling temperature difference of the cooling device in Example 1 at different temperatures of the heat sink end 3 as the current changes; according to the one-dimensional heat conduction theory, the cooling rate depends on the cooling power and thermal conductivity. At 39K, the YbInCu4-based refrigerator has a thermoelectric power factor of up to 190μW·cm-1·K-2 and a high thermal conductivity of 8W·cm-1·K-1, which ensures a fast cooling rate. The device can reach the maximum cooling temperature difference within a few seconds, and its cooling rate is much faster than that of traditional Peltier devices.

[0067] Figure 7 The cooling temperature difference of the YnInCu4 single-leg device 1 under different working current driving in Example 1. Under the optimized current driving, when the temperature of the heat sink end 3 is 38.4K, the device achieves a maximum cooling temperature difference of ~6K (maximum temperature difference ~0.5K). Figure 7 (d) is the heat sink temperature and cooling temperature driven by different working currents.

[0068] The preparation process in Example 1 was repeated to prepare a YbInCu4 single-leg device 1, which was assembled to obtain a low-temperature thermoelectric refrigeration device. The refrigeration temperature difference of the YbInCu4 low-temperature thermoelectric refrigeration device was tested as a function of the current and the temperature of the heat sink end 3. Figure 8The refrigeration temperature difference of the YbInCu4 low-temperature thermoelectric refrigeration device in Example 1 varies with the current and the temperature of the heat sink end 3. The results show that the YbInCu4 single-leg device 1 achieves a maximum refrigeration temperature difference of about 6K when the temperature of the heat sink end 3 is 38.4K, further proving that the low-temperature thermoelectric refrigeration material and device based on Thomson effect enhancement proposed in the present invention have strong applicability and repeatability.

[0069] In summary, the technical solution of the present invention has the following advantages:

[0070] 1. By utilizing the electronic phase transition process, the present invention effectively improves the thermoelectric figure of merit of the material in the low temperature region. The sudden change of electron entropy during the phase transition process causes the thermoelectric performance of the material to reach a peak near the phase transition temperature, which is significantly higher than that of traditional thermoelectric materials without electronic phase transition. This strategy for improving thermoelectric performance has important guiding significance for the development of low-temperature refrigeration materials.

[0071] Second, the thermoelectric cooling device proposed in the present invention is suitable for low-temperature environments, and further optimizes the thermoelectric performance and cooling effect through electronic phase change regulation. Its rapid response and efficient temperature difference regulation capabilities make it have broad application prospects in scientific research, low-temperature physics experiments, and precision refrigeration.

[0072] 3. The present invention combines precise experimental setup to fully utilize the Thomson effect, reduce temperature fluctuations, and maximize cooling efficiency. This innovative design achieves repeatable high-performance results in multiple different devices. In addition, in addition to the YbInCu4 material proposed in the present invention, the technical solution and measurement method in the present invention can also be applied to other materials with similar phase transitions and Thomson effects, with a wide range of material compatibility and potential applications.

[0073] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a low-temperature thermoelectric refrigeration material, characterized in that: Yb, In and Cu are uniformly mixed according to the stoichiometric ratio and placed in a tantalum crucible. They are arc-melted in a vacuum sealed environment to obtain a YbInCu4 ingot, which is then ground to obtain a YbInCu4 powder. The YbInCu4 block is then hot-pressed and sintered to obtain the target product, a low-temperature thermoelectric refrigeration material.

2. The method for preparing a low-temperature thermoelectric refrigeration material according to claim 1, characterized in that: The arc melting comprises the following steps: The uniformly mixed Yb, In and Cu are placed in a tantalum crucible, and the tantalum crucible is vacuum-sealed in an arc melting system; The vacuum-sealed tantalum crucible is placed in a container, and after evacuation, it is sealed with a flammable organic gas; The sealed container is water quenched at 1000-1200°C; The container obtained after water quenching is annealed at 750-950°C to obtain a YbInCu4 ingot.

3. The method for preparing a low-temperature thermoelectric refrigeration material according to claim 2, characterized in that: The container includes a quartz tube and an alumina crucible; The combustible organic gas includes propane and hydrogen.

4. The method for preparing a low-temperature thermoelectric refrigeration material according to claim 1, characterized in that: The molar ratio of Yb, In and Cu is 1:0.8-1.2:3-5.

5. The method for preparing a low-temperature thermoelectric refrigeration material according to claim 1, characterized in that: The specific conditions of the hot pressing sintering are: a temperature of 500-800° C. and a uniaxial pressure of 60-100 MPa.

6. A low-temperature thermoelectric refrigeration material, prepared by the preparation method according to any one of claims 1 to 5.

7. The low-temperature thermoelectric refrigeration material according to claim 6, characterized in that: The low-temperature thermoelectric refrigeration material has a thermoelectric power factor of 120 to 190 μW·cm-1·K-2 and a thermal conductivity of 5 to 8 W·cm-1·K-1 within a temperature range of 38 to 40 K.

8. The use of a low-temperature thermoelectric refrigeration material in the field of thermoelectric refrigeration according to claim 7, characterized in that: The low-temperature thermoelectric refrigeration material is used to prepare a low-temperature thermoelectric refrigeration device.

9. The use of a low-temperature thermoelectric refrigeration material according to claim 8, characterized in that: The low-temperature thermoelectric refrigeration device comprises: Vacuum chamber; A heat sink end located inside the vacuum chamber; And a leg device connected to the heat sink end through a thermally conductive adhesive, wherein the leg device is cut from the low-temperature thermoelectric refrigeration material.

10. The use of a low-temperature thermoelectric refrigeration material according to claim 9, characterized in that: The maximum temperature difference of the leg device is 5-6K when the current condition is 40-500 under the temperature range of 38-40K.

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